1st Edition

Transport Phenomena of Foods and Biological Materials

By Vassilis Gekas Copyright 1992

    Transport Phenomena of Foods and Biological Materials provides comprehensive coverage of transport phenomena modeling in foods and other biological materials. The book is unique in its consideration of models ranging from rigorous mathematical to empirical approaches, including phenomenological and semi-empirical models. It examines cell structure and descriptions of other non-traditional models, such as those based on irreversible thermodynamics or those focused on the use of the chemical and electrochemical potential as the driving forces of transport. Other topics discussed include the source term (important for the coupling transport phenomena-reaction or other intentional/unintentional phenomena) and the connections between transport phenomena modeling and design aspects. Some 100 tables provide useful summaries of the characteristics of each model and provide data about the transport properties of an extensive variety of foods.

    Transport Phenomena of Foods and Biological Materials will benefit a broad audience of chemists, biochemists, biotechnologists, and other scientists in the academic and industrial realm of foods and biological materials.

    INTRODUCTION. DEFINITIONS. Food and Bioengineering. Unit Operations and Physical Models. AIM AND SCOPE. GENERAL MODELS OF TRANSPORT PHENOMENA. RIGOROUS MATHEMATICAL MODELS. The Generalized Diffusion Equation (GDE). In One Dimension. Extension in Three Dimensions and Other Geometrics. Including Convection and Source Terms. Physical Meaning of the Time Derivatives. Methods of Solution of GDE. The Particular Transport Cases. Analogies. Mass and Heat Transfer. Momentum Transfer. The Steady-State Case. The General Resistance Model. Resistances in Series and in Parallel. Interfacial Transport and Transfer Coefficients. Heat Transfer. Mass Transfer. Momentum Transfer. Solution of the GDE with Interfacial Limitations. SEMIEMPIRICAL MODELS. Dimensionless Numbers. Momentum Transfer. Ratios of Diffusivities. The Peclet Number. The Grashof Number. The Graetz Number. The Stanton Number. The Psychrometric Ratio. Correlations. Forced Convection. Free or Natural Convections. Use of Correlations. PHENOMENOLOGICAL MODELS. Irreversible Thermodynamics. The Chemical Potential as a Driving Force. The Electrochemical Potential as a Driving Force. THE STEFAN-MAXWELL APPROACH. EMPIRICAL MODELS. CHARACTERIZATION AND PROPERTIES OF FOODS AND OTHER BIOLOGICAL MATERIALS. CLASSIFICATION AND RHEOLOGICAL BEHAVIOR. Foods. Microbial Cells. CASES OF TRANSPORT PHENOMENA. In Foods. In Biochemical Engineering. TRANSPORT PROPERTIES. Thermal Properties. Mass Transfer Properties. Sorption Isotherms. Mass Diffusivity. CELL STRUCTURE AND MULTIPHASE TRANSPORT. Description. Pathways of Transport. TRANSPORT PHENOMENA OF LIQUID PRODUCTS. HEAT AND MASS TRANSFER IN NON-NEWTONIAN PIPE FLOW. Laminar Flow. Turbulence. Rigorous Models. Semi-Empirical Models. AGITATED SYSTEMS. General Concepts. Dimensionless Numbers. TRANSPORT PHENOMENA IN SOLID FOODS. SIMULTANEOUS HEAT AND MASS TRANSFER. To the Product. Within the Product. The Crust. The Evaporation Zone. SHORT-CUT MODELS. The Regular-Regime Model. Constant Period. Penetration Period. Regular-Regime. Drying Curves. The Shrinking-Core Model. THE PROBLEM OF SHRINKAGE. The Approach of Crank. A Modified Crank Approach. Other Approaches. USE OF THE CHEMICAL POTENTIAL AS THE DRIVING FORCE. Early Attempts. The Bahia-Blanca Approach. IRREVERSIBLE THERMODYNAMICS AND SIMULTANEOUS TRANSPORT. TRANSPORT PHENOMENA AND THE SOURCE TERM. THE MASS TRANSFER SOURCE TERM: TRANSPORT AND REACTION. In Foods. Zero Order. First Order. Simultaneous Reactions. Other Models. Enzymatic Reactions. THE HEAT TRANSFER SOURCE TERM. Viscous Dissipation. Latent Heat. Radiation. Electrical Properties. Radiation Source Term. TRANSPORT PHENOMENA MODELS IN SOME UNIT OPERATIONS AND PROCESSING EQUIPMENT. PROCESSING EQUIPMENT FOR LIQUIDS. Heat Exchangers. Tubular. Plate. Scraped Surface. Cooking Extruders. Boilers. UNIT OPERATIONS WITH SOLIDS. BIOREACTORS. EPILOGUE. COUPLING TO THE DESIGN PROCESS. Macroscopic Balances. Correction Factors. FUTURE TRENDS. Rigorous Mathematical Modeling. Trends in Computational Capacity. Commercial Computer Programs. Phenomenological and Other Alternative Models. Irreversible Thermodynamics. The Chemical and Electrochemical Potential as Driving Forces. Rheological Studies. Heat and Mass Transfer Properties. Modeling in Biochemical Engineering. Cell Structure and Geometry. Instabilities and Modern Chaos Theory. Fundamental Transport Phenomena Modeling in Connection to Scale Up and Design Aspects. Closure.


    Vassilis Gekas